HP 61X Black LaserJet Toner Cartridge features HP Smart Print Supplies System - an intelligent system for carefree printing. An ideal cartridge solution for users who want to simplify monitoring and ordering their printing supplies.Compatible Printers: Troy 4100 T EX Micr Secure, Troy 4100 T Micr, HP LaserJet 4101 MFP, HP LaserJet 4100 MFP, HP LaserJet 4100 N, HP LaserJet 4100, HP LaserJet 4100 DTN, HP LaserJet 4100 TN, HP LaserJet 4100 Series, Troy 4100 Series, Troy 4100 EX Micr Secure, Troy 4100 EX Micr